Air-brake.



4 -Patented Nav. 2l, |899.

J. J. NEF.

AIB BRAKE. l(Application led Oct. 2, 1896. Renewed Oct. 27, 1899.)

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nu. 637,647. Patented Now-2|, |899. J. J. NEF.' AIB BRAKE. (Application med occ; 12,' `-159e. mmweuocn. 21, 1899.)

2 Sheets-Sheet 2.

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vadjusted slide-valve B'.

UNITED STATES PATENT FFICE.

JOHN JACOB NEF, OF NEIV YORK, N. Y., ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO THE PACIFIC INVESTMENT COMPANY, OF NEV JERSEY.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent N 0. 637,647, dated November 21, 1899.

Application lecl'October 2, 1896. Renewed October 27, 1899. VSerial No. 734,987. (No'model.)

T0 wlwwm t may concern:

Be it known that I, JOHN JACOB NEF, a citizen of the United States, residing at the city of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Air-Brakes; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Myinvention has relation to automatic governors for air-brakes, and has for its object the provision of novel means for automatically throwing the pump in and out of operation, the same being effected by the variation of the airpressure due to the alternate accumulation of pressure by the pump and the reduction of pressure proceeding from the operation of the brake.

My invention also consists in the novel construction, combination, and arrangement of parts hereinafter described.

Referring to the accompanying drawings, Figure l is a sectional View of my improved governor, and Fig. 2 a sectional View on the line 2 2 of Fig. 1. Fig. 3 shows thevarious parts of the system and their relative positions.

A designates a cylinder having a head A', with stuffing-box A2, through which passes a piston-rod A3, carrying a piston A4. The piston-rod A3 is connected to a clutch C or other connecting device interposed between the moving parts of the pump I? and its actuating mechanism O. A spring A5 is interposed between and bears against' the head A( and the piston A4, a recess being formed in head A6 to receive one end of the spring.

Upon the side of cylinder A is bolted a valve-chamber B, which contains a specially- One end of the chamber B is cylindrical and contains a properly-packed piston B2, into which is screwed a hollow piston-rod B5. A little below the center of this hollow piston-rod are screwed on two hexagonal nuts c' l,with shoulders that embrace the projection I from the back of slide-valve B. One end of the chamber B is closed by a flanged head D, in the center of which is an adjustable screw-plug D', and a spring D2 is interposed between the plug D and a seat B7 at the bottom of hollow piston` rod B5, so that by the adjustment of the plug the resistance of the spring may be increased or diminished. Ports E and F lead from the valve-chamber to the cylinder A, but at different sides of the piston contained in said cylinder, and a passage G leads from the hollow of slide-Valve B' to the open air.

H is a pipe leading from the reservoir R, Fig. 3, in which the compressed air is stored. The positions of the ports E F are such that when the piston B2 is raised by the increase of pressure in the pipe I-I, leading from thereservoir, the hollow piston-rod B5 rises and carries with it the slide-valve B', connected thereto, thereby closing the port F from the stored energy in the reservoir and opening an escape to the atmosphere through port G for air on the upper side of piston A4. At the same time port E is opened, admitting air to the under side of piston A4, thereby elevating the piston and disengaging the pump from its actuating mechanism. Then the port E is admitting air to the under side of piston A4, Ashould the pressure fail to elevate the piston and disengage the moving parts of the pump from its actuating mechanism, thereby allowing the pump to compress air above the maximum point, the surplus pressure will through its action on piston B2 carry the slidevalve above the exhaust-port G and form a free escape of air from the reservoir R to the atmosphere.

Operation: The parts being in position, as shown in the drawings, let it be supposed that the reservoir contains no air and the pump is thrown into operation by the acting of the spring A5, interposed between the head A( of cylinder A and piston A4. This spring is of sufficient tension to connect the moving parts of the pump to its actuating mechanism until sufficient air has been accumulated to hold this connection. As the air from pipe H enters the valve-chamber B it passes through port F, leading to the upper side of piston A4. This position is maintained until the pressure reaches the maximum, whereupon the piston B2 is forced back against the resistance of the spring D2, closing the port F from the stored energy and forming a communication from upper end of cylinder A through it IOO to the openr air through passage G. At the same time port E is opened, allowing the air` `to enter the cylinder A below the piston and elevatethe same. The position of the parts last described is maintained while the pressure is at the maximum, and the pump having been stopped by the elevation of the pisi ton A4 remains inactive so long as the piston remains in its` elevated position. The gradual decrease of the air-pressure to the miniy fectly automatic manner solely by the variation in pressure by the operation of thebrake.

Having described my inventiomlclairn* l. In an air-brake system the combination of a cylinder and a piston therein connected to theA pump-operating mechanism, a valvechamber having a port adapted toreceive air under pressure, supply-ports affording a passage for said air from said valve-chamber to said air-cylinder on each side of said piston, a reciprocating slide-valve arranged in said valve-chamber and adapted to alternately close each of :said ports leading from said valve-chamber to said air-cylinder and open the other, means whereby said valve is oper.- ated in one direction by thepressure of said air in said valve-chamber above a predetermined point, and means for operating said valve in an opposite direction when the airpressnre falls below said predetermined point substantially as described. j

2. In an air-brake system the combination of a cylinder and a piston therein connected to the pump-operating mechanism, a valvechamber having a port adapted to receive air under pressure, supply-ports aordinga passage for said air from said valve-chamber to said air-cylinder on opposite sides of said piston, an exhaust-port, a valve in.l said valve- `chamber adapted to alternatelyclose each of said supply-ports 'and open the rvother, and also .toV open the exhaust-port to that end of the cylinder to which the supply is closed, a piston connected to said-valve arranged and adapted to be operated in one direction by the pressure of said air in saidvalve-chamber above a predetermined point, and by a spring Ain the other direction, substantially as described.

3. The combination in an air-brake system of a pump and pump-operating mechanism of an air-cylinder and piston, a spring for forcing the piston in one direction toconnect the p'ump with its operating mechanism, avalvechamber, a port leading from said valvechamber to the opposite side` of said piston, an exhaust-port, a valve arranged in said valve-chamber and means acting under variations of air-pressure-upon a relatively-fixed part of the valve mechanism for ,operating said valve to alternately open and close the air-cylinder to the valve-chamber and the exhaust, substantially as described.

4. The combination in an air-brake system of a pump and pump-operating mechanism of an air-cylinder and pistou, a valve-chamber, supply-ports connecting said valve-chamber with said air-cylinder on oppositesides of said4 piston, lan exhaust-port, a slide-Valve working in said chamber and arranged and adapted to open vcommunication with each end of the cylinder whileV closing the opposite end and opening same to the exhaust, a i

piston adapted to beoperated in one direction by air under pressure above a predetermined pointA and having a hollow stem to which the valve is connected and a spring seated in said 'piston-stem arranged and adapted to operatethe piston and move the valve inthe opposite direction when the air falls below said predetermined point, substantially as described.

In testimony whereof I have signed my name to this specification inthe presence of two subscribing witnesses.

' JOHN JACOB NEF.

Witnesses:

IDA NATHAN, R. L. CUTHBERT. 

